Usually one can adjust paragraph indent with
but that fails for the apa class. Is there another way to get rid of this indents in this class?
I must qualify my comment.
I used the two following examples to test my statement and I noticed that the command:
in the preamble will do the job.
In the next run I noticed that
Based on this MWE (that is your task) you have to change
Proof: A minimal working example (MWE) ist the best way to illustrate a problem. q.e.d.